1. Field of the Invention
The present invention pertains to a resilient railroad tie cover of a generally rectangular configuration which when attached to railroad ties increases the resiliency of the rail track system while increasing the service life of wooden railroad timber ties. More particularly, the invention provides a railroad timber tie cover susceptible of manufacture and shipment in a flat configuration having a plurality of grooves designed to dampen and distribute vibrations of low frequency and load forces in timber ties while aerating and removing moisture and water from timber ties. The novel configuration and design of the tie cover allows the tie cover to be shipped in a flat configuration and thereafter be cut and installed to form a three dimensional timber tie cover at the work site to accomodate varying lengths of wooden rail ties that is particularly useful in special track sites such as is employed at rail switches. The utilization of a plurality of channels and grooves in the railroad timber tie cover or sleeve not only assists in the dampening and distributing of load during the train passage but also provides improved rail operation by the reduction of noise and the increase of resiliency in rail tracks with or without ballast.
2. Description of the Prior Art
The prior art employs a variety of fastening devices in combination with resilient pads for increasing the resiliency of railroad track with and without ballast. Conventional railroad track systems utilized in the United States predominantly employ a ballasted bed of broken stones which support wooden railroad ties and impart some resilience to the railroad system. The utilization of ballast is the predominant method of imparting resiliency to railroads in the United States which has also resulted in harder and noisier railroad tracks. In some applications, however, such as in tunnel operations or in environments where the utilization of deep beds of ballast are not practical, resilient pads have been interposed between the railroad track and the railroad tie to increase the resiliency of the railroad system. One such application of a rubber pad to increase the resiliency of a rail positioned on a portion of a wooden tie is illustrated in U.S. Pat. No. 2,779,543.
In many track applications in European countries, wooden ties are not utilized and railroad track systems are in widespread use that do not use ballast. To obtain resiliency, elastomer pads or block tie boots which fit over and around the concrete railroad ties are employed. Illustrative of railroad track systems utilizing railroad track without ballast is U.S. Pat. No. 3,289,941. In such systems, resiliency is imparted by employing a rubber boot or sheath interdisposed between a concrete tie block and the continuous floor formed of cement, concrete or black concrete. Unlike the present invention, this prior art system employs a fluid tight sheath which is not designed to provide drainage and aeration of a wooden tie. Due to the shape of the prior art, such prior art cannot be used with conventional timber ties.
The known prior art systems in use in the United States for wooden railroad timber ties employ rubber pads and similar resilient supports to increase the resiliency of the railroad systems. Such systems are not designed for the purpose of increasing the operational life of the wooden railroad tie by assisting in the drainage of water from the wooden rail tie and drawing air into and around the railroad tie by the loading or unloading of the railroad tie systems such as occurs during the passage of trains. The application of a railroad tie cover of the present invention, constructed of an elastomer material, is designed to not only increase the resiliency of traditional railroad beds with ballast as utilized in American railroad systems, but also to increase the life of the railroad timber tie by allowing moisture to be drained from railroad timber ties while providing necessary aeration to increase the service life of wooden railroad ties.
In the application of the rubber pads to U.S. prior art systems, the rubber pad has traditionally been interposed between the wooden tie and the steel tie plate upon which the steel rail is placed in order to impart resiliency to the overall system. The present invention unlike the prior art does not attempt to increase the resiliency of the overall system by the utilization of a pad between the railroad tie and the rail tie plate. The present invention is instead directed to the utilization of a resilient covering for a railroad tie, that is interposed between the railroad tie and a railroad bed which may or may not utilize the ballast. The present invention employs a railroad tie cover for railroad systems with and without ballast wherein the overall resiliency of the system is achieved by the modification of the relationship between the thickness of the supporting surface of the railroad tie cover in conjunction with the depth and number of grooves that further provide for the aeration and channeling of water away from the wooden railroad tie.
The invention further provides a railroad timber tie cover that is particularly advantageous for application to wooden railroad ties while allowing it to be manufactured, shipped and stored at a minimum cost as a result of its novel configuration and design. The railroad tie cover is susceptible to extrusion or molding processes that form a flat and substantially rectangular pad which may thereafter be installed on traditional wooden railroad ties by bending and fastening the ends around the sides of the railroad timber tie. In addition, the railroad timber tie covers can be installed on standard timber tie lengths or cut to various sizes at the work site to accomodate timber tie lengths of varying sizes which are predominantly employed at rail switching and other special track work sites.
The utilization of the novel railroad timber tie covers of the present invention further allows the dissipation of shock and vibration that impair the integrity and useful life of the railroad tie fastening system while at the same time prolonging the useful life of the railroad tie. The utilization of grooves and channels in the tie cover center support for the tie of the present system in addition to removing moisture and prolonging the life of the railroad timber tie also reduces rail support hardness and improves the performance of U.S. rail systems by noise reduction and the necessity of maintenance on railroad tie systems utilizing wooden ties.